Brian Jackson: Ever since I can remember, I've wanted to be clever. Some people are born clever, same way some people are born beautiful. I'm not one of those people.
Lucy says the source of the quote "To err is human" as Alexander Pope's "An Essay on Man." The quote actually originates from Pope's earlier work, "An Essay on Criticism."
Catherine Tate plays James McAvoy's mother in the movie, even though in real life she's only 11 years older than him.